# File lib/minitest/unit.rb, line 228
    def assert_same exp, act, msg = nil
      msg = message(msg) {
        data = [mu_pp(act), act.object_id, mu_pp(exp), exp.object_id]
        "Expected %s (oid=%d) to be the same as %s (oid=%d)" % data
      }
      assert exp.equal?(act), msg
    end